In the communications industry, as data transmission rates have steadily increased, crosstalk due to capacitive and inductive couplings among the closely spaced parallel conductors within the jack and/or plug has become increasingly problematic. Modular connectors with improved crosstalk performance have been designed to meet the increasingly demanding standards. Many of these improved connectors have included concepts disclosed in U.S. Pat. No. 5,997,358, the entirety of which is incorporated by reference herein. In particular, recent connectors have introduced predetermined amounts of crosstalk compensation to cancel offending near end crosstalk (NEXT). In some connectors, stages of compensation are used to account for phase shifts from propagation delay resulting from the distance between the compensation zone and the plug/jack interface. As a result, the magnitude and phase of the offending crosstalk is preferably offset by the compensation, which, in aggregate, has an equal magnitude, but opposite phase from the offending crosstalk.
Recent transmission rates, including those in excess of 500 MHz, have exceeded the capabilities of the techniques disclosed in the '358 patent. Thus, jacks having improved compensation characteristics are needed.
There is a phase shift from an installed plug to the compensation zones in a jack which is dependent on the distance from the plug/jack electrical interface to the printed circuit board (PCB) containing compensation elements, which may be a flexible PCB. This phase shift is proportional to frequency and the effective compensation is dependent on the magnitude of phase shift. It is therefore advantageous to minimize this distance and phase shift to maximize the frequency range over which sufficient compensation is attained.